Compressor



Dec. 25, 1928.

W. FOURNESS CQMPRESSOR Filed March 8, 1927 2 Sheets-Sheet ATTOB NE VDec. 25, 1928. 1,696,674

w. FOURNESS COMPRESS 0R Filed March 8, 1927 2 Sheets-6h?) 2 ME TOE/IY/LFEED Foue/vssa ATTOENEK Patented Dec. 25, 1928.

UNITED STATES.

WILFRED FOURNESS, OF PASADENA, CALIFORNIA, ASSIGNOBQ BY MESNE ASSIGN-PATENT OFFICE.

MENTS, TO THE FOURNESS DEVELOPMENT CORPORATION, OF NEW YORK, N. Y,

A CORPORATION OF NEW YORK.

COMPRESSOR.

Application filed March 8, 1927. Serial No; 173,759.

pressors? I describe a compressor structure enclosed'in a housing, andhaving angularly displaced cylinders, and pistons operated by eccentricsto reciprocate therein. Valve pistons are also provided which controlopenings from the cylinders to the casing, and

similarly operated. In that form, the eccentrics serve to operateeccentric blocks, and upon these blocks are accommodated several slides,carrying the pistons operating in the stationary cylinders. It isobvious that such an arrangement involves somewhat complex mechanism. Itis one of the objects of my invention to provide an eccentric operatedcompressor mechanism that is much simpler than the form just referredto, thereby making it possible to manufacture such compressorsinexpensively.

It isanother object of my invention to improve in general reciprocatingcompressors of this type.

In such compressors, the valve pistons must of course be operated insynchronism with the main pistons, and this is accomplished asheretofore stated, by the aid of a valve eccentric. Usually the valvestroke lags behind that of the piston stroke, whereby the outlet valveis opened when the pistou nears the end of its stroke, and closes soonbefore the piston reverses. It is thus evident that the angular settingsof the operating eccentrics must be such as to produce this effect. Whenoperating the compressor shaft always in the same direction, it is asimple matter to fix the relative positions of the eccentrics once andfor all to cause proper operation of the compressor.

However, it sometimes happens that the source of motion for thecompressor shaft reverses in direction, as for example when that sourceis an electric motor. Under such circumstances, the relative angularpositions of the valve eccentric and the piston eccentric must bechanged. It is accordingly another object of my invention to make itpossible to adjust these angular positions.

It is still another object to arrange matters in such a way that thechange in angular position is produced automatically in response to thereversal of the direction of rotation.

My invention possesses many other advantages, and has other objectswhich may be made more easily apparent from a consideration of oneembodiment of my invention. For this purpose I have shown a form in thedrawings accompanying and forming part of the present specification. Ishall now proceed to describe this form in detail, which illustratesthegeneral principles of my invention; but it is to be understood that thisdescription is not to be taken in a limiting sense, since the scope ofmy invention is best defined by the appended claims.

Referring to the drawings:

Figure 1 is a sectional perspective view, showing a compressor embodyingmy invention;

Fig. 2 is an elevation of an eccentric block that is used in connectionwith the compressor shown in Fig. 1;

Fig. 3 is a side view, partly in section,

of an eccentric assembly incorporating my invention; and n Fig. 4 is asectional view, taken along plane 44 of Fig. 3.

In Fig. 1, there is shown a casing 11, with radiating fins 12, that canserve as an enclosure for the operating parts of the compressor. Thiscasing is shown as a casting, with apertured standards 13 by the aid ofwhich it may be appropriately supported on a base or the like. Thecasing 11 has a removable wall portion 14 to provide access to theinterior, and also to support certain of the parts of the compressor, ashereinafter described. The removable wall 14 carries a pipe-like boss 15in which is formed the inlet passageway 16, into which a pipe can bescrewed at the threaded mouth 16. This inlet passageway serves toconduct the expanded refrigerant to the compressor, which refrigerant isthereby compressed, and escapes through the outlet openingl? on the topof the casing.

The wall 14 alsoprovides'in this instance for the insertion of a driveshaft 18, whereby motion is imparted to the compressor. For thispurpose, the wall is provided with a comparatively long bearing boss 19.This boss has a bushing 20 serving as a bearing. In'order to provide afluid tight packing and prevent substantial leakage of fluid from theinterior of casing 11, I provide a plurality of conical packing rings 31of resilient fibrous material, which surround shaft 18 and are urged inclose contact with the bushing 20 by the aid of a compression spring 32.A plug 33 screwed into boss 19 serves to regulate the compression ofthis spring.

- In the present instance, a compressor body 34 is formed integrallywith wall 14: Upon this body are supported cylinder blocks such as 37;two are shown in the drawings, arranged radially of shaft 18 andopposite each other. However, there are preferably four such blocks,angularly displaced from each other around the axis of shaft 18, thedisplacement being 90; Each cylinder block has a flange 35 which seatsinto a corresponding depression on the outer surface of body 34. Apacking ring 36 is interposed between the flange and the body 37, andscrews 38 serve to bolt the block securely in place.

The arrangement is such that the inlet passageway 16 communicates withthe interior of the body 34 whence the gas to be compressed can enterthe, cylinders. From the cylinders, the compressed gas is expelled intocasing 11. Each block 37 therefore has a cylinder bore 39, radial withrespect to shaft 18 in which piston 40 is reciproeated. Each cylinderblock also has a slot 41 which is partly uncovered at the beginning "ofthe stroke, to permit gas to enter the bore 39 from body 34.Furthermore, a port 42 is provided adjacent the end of the bore forpermitting the compressed gas to flow out of the cylinder. 7

This outlet port 42 is controlled in each instance by a reciprocatingvalve piston 43 operating in a valve bore 44 that parallels the cylinderbore. The-valve pistons 43 are arranged to operate in such manner thatthe port 42 is open during the latter part of the travel of main piston40, but is closed soon before the piston 40 starts retracting. Themanner in which the rotation of shaft 18 causes the pistons and valvesto recipro cate can be most clearly understood from Figs. 2, 3 and 4. v

Locatedon shaft 18 are a pair of eccentries, 45 and 46. Each of theseeccentrics operate in blocks, such as 47 and 48 each of which isprovided with a bushing bearing 49 or 50. It is evident that if blocks47 and 48 are restrained against rotation but not against radial motion,then rotation of cocentrics 45 and 46 will cause the center of the borein the blocks to move in 'a circle around the axis of shaft 18, therebycausing the blocks to be moved closest successively to the angularlydisplaced cylinder blocks. Therefore, if these blocks be arranged tooperate on pistons 40 and 43, a reciprocation could be effected; butprovision of course must be made to permit the blocks to slidetransversely of the piston axes. In my prior patent, this wasaccomplished by yokes, which however I obviate in a simple manner in mypresent invention.

-' For this purpose, I provide a sliding tongue and roove connectionbetween the pistons and the blocks. This connection interlocks thepistons and the blocks, whereby the block movement serves to pull aswell as push the pistons; and of course the pistons working in theirbores effectively restrain the blocks from being carried around with theeccentrics. I As shown in Figs. 3 and 4, pistons 40 each have a flange51 which may be round; and a tongue 52 is formed on the flange thatcoacts with groove 53 on block 47. The overhanging lip 54 on the blockprevents movement of the pistons 40 radially of block 47 but the groovepermits transverse movement of the block with respect to the piston. Itis evident that this keyed construction needs no further lock, for thetongue 52 cannot be withdrawn from slot 53 when pistons 40 are in thecylinder bores.

The valve pistons 43 are of entirely similar construction, the tongues55 thereof operating in grooves 56 on the block 48. Furthermore, it isfound that for proper operation, thevalve pistons 43 must operate 120behind the main pistons 40; and as shown in Fig. 4, this requirementnecessitates having the eccentric 46 for the valves set at an angle of'120 behind the main eccentric 45, the rotation of shaft 18 beingcounterclockwise as viewed in this figure. In case the shaft 18 shouldbe reversed, it is evident,

that the valve eccentric would lag by 240 instead of 120 as it should.

In order to overcome this, I provide an angular adjustment for one ofthe eccentrics about shaft 18. Thus eccentric 46 can have a circularslot or depression 57 of about 240 extent, which is cut in its. faceadjacent eccentric 45, and is freely movable on shaft 18. ,Its movementis however, limited by a key 58 carried by the shaft and working in theslot. This key can also serve to hold eccentric 45 in place on theshaft. \Vhcn the rotation of shaft 18 is counterclockwise, the key 58 isin the position indicated in Fig. 4, engaging one wall of slot 57 anddriving the loose eccentric thereby. Now if the shaft 18 should bereversed, the eccentric 46 would momentarily remain stationary, untilkey 58 travels to the other wall of the slot. When that happens, and alllost motion is taken up, the main eccentric 45 is in the alternativeposition shown by the dotand-dash' lines. The valve eccentric thenfollows the main eccentric with a lag of 120, which is the desiredrelation.

not

It is thus seen that a lost motion connection is provided between thevalve eccentric and the shaft 18, which is automatically taken up uponmovement ofshaft 18 in either direction.

Referring now again to Fig. 1, the remaining mechanical features of thecompressor can be outlined. The compressor body 34 has an end closure 59in which there is a bearing 60 for shaft 18. A disc-like closure 61covers this bearing. A connection 62 is provided in this closure for asafety valve 63, which permits escape of gas back to body 34, if itattains undesirably high pressure in the Casing 11. Furthermore, oil 64is present in the bottom of casing 11, which serves as a reservoir forlubricant. Of course the vapor coming into the compressor at the inlet16 may carry some lubricant, which finally settles and is commingledwith oil 64.

For lubrication purposes, a pipe 65 connects the oil 64 with an aperture66 in the bearing 60, the gas pressure in housing 11 serving to forceoil upwardly into said pipe. The shaft 18 has an axial aperture 67through which oil is forced, and the eccentrics 45 and 46 havepassageways 68 and 69 communicating with this axial aperture and alsowith the bearings 49 and 50 of the blocks 47 and 48.

The mode of operation is apparent from the foregoing; As the eccentrics45 and 46 are rotated, the pistons 40 and 43 move in and out of theirbores, and the blocks 47 and 48 slide along the tongues 52 and 55attached to these pistons. The valves operate to open the outlet ports42 near the end of the stroke, to pass the compressed gas into casing11.

' I claim:

1. In a compressor, a cylinder, an eccentric rotatable about an axisnon-parallel with that of the cylinder, :1 block in which said eccentricrotates, and a piston operating in the cylinder, said piston beingprovided with an integral extension having a sliding connection with theblock for causing the block to reciprocate the piston as the eccentricis rotated, and for permitting relative motion between the piston andthe block transverse to the cylinder axis.

2. In a compressor, a cylinder, an eccen-' tric rotatable about an axisnon-parallel with that of the cylinder, a block in which said eccentricrotates, and a piston operating in the cylinder, said piston having anintegral extension, said block and extension having a tongue and grooveconnection permitting relative movement between the piston and the blockin a direction transverse to the axis of the cylinder.

8. In a compressor, a cylinder, an eccentric, the axis of the cylinderbeing perpendicular to that of the eccentric, a piston opabout an axis,a plurality of cylinders angularly spaced aroundsaid axis and havingaxes radial to said axis, a block in which said eccentric rotates, apiston for eachof the cylinders, each of said pistons having an integralextension and a transverse sliding connection between each of theextensions and the block.

1 5. In a compressor, an eccentric rotatable about an axis, a pluralitof cylinders angularly spaced around said axis and having axes radialtosaid axis, a block in which said eccentric rotates, a piston for each ofthe cylinders, each of said pistons-having an integral extension, and atongue and roove sliding connection between each of t e extensions andthe block, said connection being transverse and of such form as toprevent separation between the pistons and the block while permittingrelative sliding.

6. In combination, a piston, a cylinder, rotatablemeans for causingrelative motion between the piston and the cylinder, valve mechanism forthe cylinder operated b said means, and means whereby the operation ofthe valve mechanism stays properly timed for either direction ofrotation of the means that causes relative motion between the piston andcylinder, comprising a lost motion connection between said latter meansand one of the mechanisms operated thereby.

7. In combination, a piston, a cylinder in which said piston operates, arotatable shaft,

mechanism whereby the shaft operates the piston, a valve mechanism forthe cylinder also operated by the shaft, and a lost motion connectionbetween one of said mechanisms and the shaft, whereby the valvemechanism remains properly timed for either direction of rotation of theshaft.

8. In combination, a shaft, a pair of coeentrics driven by the shaft,one of said eeccntries having a lost motion connection with the shaft,of such angular extent that for either direction of rotation of theshaft, one of said eccentrics leads the other by the same angle, apiston and a cylinder operated for relative motion by one of saideccentrics, and a valve mechanism therefor operated by the othereccentric.

' 9. In combination, a shaft, a pair of cocentrics, one of saideccentrics being rigidly fastened to the shaft, the other eccentrichaving a groove adjacent the shaft of circular form but of less angularextent than a complete circle, a key carried by the shaft and operatingin the groove in such manner that the eccentric is driven thereby assoon as the key moves to the end of the groove, a piston and cylinderoperated by one of said eccentrics, and a valve mechanism for 5 thecylinder operated by the other eccentric, the angular extent of thegroove in one of the eccentrics being such that the angular lag betweenthe two eccentrics remains the same for either direction of rotation ofthe shaft. It)

In testimony whereof I have hereunto set my hand.

WILFRED FOURNESS.

